Sinuous spring forming machine



May 14, 1968 H. HOPKES, JR

SINUOUS SPRING FORMING MACHINE AE5 Sheets-Sheetl l Filed Oct. 19, 1965 BY l May 14, 1968 H. HOPKES, JR

SINUOUS SPRING FORMING MACHINE 6 Sheets-Sheet 2 Filed Oct. 19, 1965 INVENTOR. #f77/y Hap/has, JG@

/ BY I HEERDE:

May 14, 1968 H. HOPKES, JR

SINUOUS SPRING FORMING MACHINE` e sheets-sheeiws Filed Oct. 19, 1965 /Vefy jm,

H. HOFKES, JR

SINUOUS SPRING FORMING MACHINE 6 Sheets-Sheet 4 .filed Oct. 19, 1965 INVENTOR. H6777? /70 )9341s, .7?.

May 14, 1968 H, HOPKES, .1R

SINUOUS SPRING FORMING MACHINE 6 Sheets-Sheet Filed Oct. 19, 1965 May 14, 1968 H. HOPKES, .1R

SINUOUS SPRING FORMING MACHINE 6 Sheets-Sheet 6 Filed Oct. 19, 1965 I l xl l: .f t: K

INVENTOR. H6772? /VO/ves, .75x BY l #Tray/vifs.

United States Patent O 3,382,896 SINUOUS SPRING FORMING MACHINE Henry Hopkes, Jr., Alte Land Ste 17, Kuesnacht, Zurich, Switzerland Filed Oct. 19, 1965, Ser. No. 497,872 9 Claims. (Cl. 1410-71) ABSTRACT GF THE DISCLOSURE Sinuous spring strips are formed to have spaced parallel bars joined by alternate oppositely disposed arcuate loops. As the next adjacent bar is folded into position, a striking element on the forming arm engages the earlier formed arcuate loop and reshapes it to a different form such as a straight section disposed normal to the parallel bars.

Various types of machines have been employed heretofore in producing sinuous spring strips having straight end portions which were large and costly and which were only satisfactory for high production requirements.

It is one object of the present invention to provide a machine `and method for producing straight or reformed loops at the side edges of the strip on revamped machines now obtainable in the trade.

It is a further object of the invention to add to a spring forming machine obtainable in the trade a loop forming pin and a loop reforming nger which reversely bends the loop a degree to produce straight portions or reversely bent loops at the side edges of the spring.

It is a still further object of the invention to modify a standard spring machine so as to change the loop to form a straight section at the side edges of the spring strip immediately after the wire thereof was bent around a forming head.

It is a general object of the invention to provide a machine and method for forming straight sections at the side edges of a sinuous spring strip which is simple in construction, positive in operation and economical of manufacture.

Other objects and features of novelty of the invention will be specifically pointed out or willbecorne apparent when referring, for a better understanding of the invention, to the following description taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a broken view in elevation of a standard spring forming machine modified in accordance with the present invention to produce straight sections at the side edges of a spring strip;

FIGURE 2 is a plan view of the machine illustrated in FIGURE 1;

FIGURE 3 is a sectionall view of the structure illustrated in FIGURE 1, taken on the line 3 3 thereof;

FIGURE 4 is an enlarged broken view of the structure illustrated in FIGURE 2, as viewed within the circle 4 thereof;

FIGURE 5 is an enlarged broken sectional view of the structure illustrated in FIGURE 2, taken on the line 5-5 thereof;

FIGURE 6 is a sectional View of the structure illustrated in FIGURE 5, taken on the line 6-6 thereof;

FIGURE 7 is an enlarged broken sectional view of the structure illustrated in FIGURE 1, taken on the line 7--7 thereof;

f 3,382,896 ce Patented May I4, 1968 FIGURE 8 is a sectional View of the structure illustrated in FIGURE 7, taken on line 8--8 thereof;

FIGURE 9 is a view of the structure illustrated in FIGURE 7, after the completion of the cut-off and dieforming operation;

FIGURE l0 is a sectional view of the structure illustrated in FIGURE 9, taken on the line 10--10 thereof;

FIGURE ll is a sectional view of the structure illustrated in FIGURE l0 taken on the line 11-11 thereof;

FIGURE 12 is a sectional view of the structure illustrated in FIGURE 10 taken on the line 12-12 thereof;

FIGURE 13 is a View of the structure illustrated in FIGURE 1, showing the opposite side of the machine;

FIGURE 14 is a view of structure similar to that illustrated in FIGURE 4, showing another form of the invention;

FIGURE l5 is a broken view of a side edge of the spring strip showing the straight side portion formed in the device illustrated in FIGURE 4;

FIGURE 16 is a broken View of a side edge of the spring strip showing the reversed side edge portion formed in the device illustrated in FIGURE 14;

FIGURE 17 is a plan view of an end of a spring strip mounted in a slip secured to a rail of a seat frame; and

FIGURE 18 is a sectional view of the structure illustrated in FIGURE l7, taken on the line 18-18 thereof;

The basic machine modified to practice the present invention is one long used in the art and embodies a bed 20 mounted on four legs 21 joined together at the bottom by a plate 22. A wire 23 which is to be fed through the machine to form the spring strip passes through a straightening device 24 of a type well known in the art. The wire is directed through a wide slot 25 to the area of a spring forming ring 26 which rotates on a fixed annular carn body 27. A worm wheel 28 is mounted on a hub 29 which is rotatably mounted on the end of a shaft 31 on which the cam body 27 is secured, The hub has a flange 32 which supports the forming ring 26 being secured thereto by a plurality of screws 33. A worm 34 has a section 35 in which the thread is disposed at an angle to the worm axis while a section 36 has the thread disposed normal to the axis. This provides a step advancement to the drive of the worm wheel 28 and the forming ring 26 with dwell time therebetween.

The forming ring 26 has a plurality of radially dispo-sed apertures 37 provided with enlarged shouldered recesses 38 extending to the periphery of the ring 26. Pins 39 extend within the apertures 37 having enlarged heads 41 which are moved within the shouldered recesses 38 by the cam periphery of the cam body 27. The pins 39 have a linger 42 extending outwardly thereof into a slot in the wall of the apertures 37 to reta-in the pins from turning. The worm 34 is driven from a shaft 43 through a pair of helical gears 44, one of which is lixed to a shaft 45. A pair of gears 46 and 47 are secured to the shaft 45, the teeth of the gear 46 being in mesh with those of a pinion 48 mounted on a shaft 49. The shaft has a pulley 51 thereon which is driven by a belt S2 from a pulley 53 on a shaft 54 of a motor 55 secured to the plate 22 by bolts 56. The teeth of the gear 47 arein mesh with the teeth of a gear 57 which is secured to a suitably journaled shaft 58 having an eccentric 59 at each end. The eccentrics drive a pair of adjustable links o1 in timed relation to each other, one of the links moving forwardly while the other link moves rearwardly. A pair of bellcranks 62 and 63 are supported on the bed by pivots 60. The outer arms of the bellcrank 62 and 63 are connected by universal pivoted joints 64 to the ends of the links 61. The inner arms 65 of the bellcranks 62 and 63 carry a boss 66 having a head 69 on a stern 67, engaged by a spring 68 about the stem which urges the head a predetermined distance from the end of the hub. The extend-ing head 69 of the pin pulls and bends the wire 23 when the arm 65 is swung clockwise to the position illustrated in FIGURE 2. When in this position, the head 69 is moved upwardly by the head 41 of an aligned pin 39 which is moved upwardly by the forming ring 26 as it is advanced over cam body 27. The head 41 receives the loop of the wire 23 from the head 69 as the head 41 is moved upwardly. Thereafter the bellcrank 63 is moved counterclockwise and the bellcrank 62 is likewise moved counterclockwise to have its head 69 engage the wire 23 and form a loop therein above a pin 41 in the adjacent rows of pins 39. The formed loop is received by the head 41 as the associated pin 39 is cammed upwardly to move the head 69 into the boss 66. In this manner the wire is bent back and forth into sinuous form as the bellcranks are driven by the links 61 and the body 26 is advanced. This advancement occurs by steps having a dwell time therebetween produced by the straight and angular thread sections and 36 on the worm 34.

Each of the arms 65 carry a boss 71 having a finger 72 adjustably mounted therein. A boss 73 on the end of the linger 72 is located in position to engage the wire portion 74 and deflect it inwardly into a cavity 75 in the facing side of the head 41, as clearly illustrated in FIGURE 4. The wire portion 74 is over-stressed beyond a straight position which when released by the boss 73 will be substantially straight and form a straight side for the resulting spring strips. Heretofore the arcuate loops were hard and 4resisted bending so that the deflection of the spring was resisted by the torsion in the straight bar portion 76 of the spring strip. The straight side portions 74 are capable of bending and provide a different action to the resulting spring strip from that having end portions formed on a radius. The forming of the Wire portion 74 occurs at the end of the swinging movement of the bellcranks 62 and 63. During the movement of the bcllcranks Iaway from the head, the forming ring 26 is stationary and another head 41 is so located as to be beneath the head 69 near the end of its movement with the wire. The head 69 will be moved upwardly when the head 41 is cammed upwardly as the forming ring 26 is advanced another step to locate a head 41 in the adjacent row in posit-ion to receive the next turn of the wire. The heads 41 and the recesses 38 are so shaped that the pins 39 can be removed and reversed 180 so that arcuate loops can be formed about the opposite sides of the heads 41 from that containing the recesses 75 in case a spring strip having this type of loop at the side edges would be desired.

The machine has a device in which the formed spring strip may have an arc formed therein and lengths may be cut therefrom while the ends are formed to receive a supporting clip. A frame 81 is supported beneath the bed 20 into which the formed spring strip 82 is pulled by a toothed wheel 83 mounted on a shaft 84. A sprocket 85 is secured on the driven shaft 49 for driving a chain 86 and a sprocket 87 mounted on a shaft 88 journaled in the frame 81. A pinion 89 on the shaft 88 drives a gear 91 mounted for free rotation on a shaft 92 which is suitably journaled within the frame. The gear 91 carries a bevel gear 93 the teeth of which mesh with the teeth of a bevel gear 94 which is mounted on a shaft 95 suitably journaled Within the frame 81. The shaft 95 has a worm 96 thereon which is a copy of the worm 34 above described which advances a worm wheel in steps. The worm 96 drives a worm wheel 97 which is secured to a shaft 98 suitably journaled within the frame 81. The shaft 98 carries a gear 99 which is in mesh with a gear 101 secured 4 to the shaft 84. This shaft drives the toothed wheel 83 to positively advance the formed strip 82 in increments of advancement through the cutoff and forming device so that the strip is not advanced during the cutting and forming operation.

The shaft 98 drives a gear 102, the teeth of which mesh with those of a gear 103 whose teeth mesh with those of a gear 104. The gear 103 is mounted on a stub shaft 105 fixed to an adjustable plate 106 which is pivoted about the shaft 198. The gears 102, 103 and 104 form a timing train by which a disk 107 fixed relative to the gear 104 is advanced to move a cam finger 108 relative to an arm 109 which is pivoted on a stub shaft 105. The arm 109 has an extending branch 111 connected by a rod 112 to an arm of a bellcrank 113 by a pivot 114. The bellcrank is pivoted on a stub shaft 115 with the extending arm 116 having a finger 117 projecting Within a slot of a retractable shoe 118. A spring 119 is located between a boss 121 on the frame and the bellcrank 113 for urging the bellcrank and the arm 109 counterclockwise. By changing the gears 102, 103, the rate of advancement of the cam finger 108 is adjusted for advancing a predetermined length of the formed strip 82 before the finger 108 operates the arm 109 and the cutoff mechanism.

A belt 122 is carried around the formed strip 82 and the toothed wheel 83 and about idler rollers 123, 124 and 125, the latter of which is mounted on a slide 126 adjustably positioned by a screw 127. By adjusting the position of the slide 126, the tension of the belt about the formed strip 82 is controlled as well as the arc permanently set in the length of the spring strip. The arc assists the spring strip to resist downward deflection when loaded.

A cutoff press 131 is mounted on the frame 8-1 having a fixed die 132 and a movable die 133. The die 133 is mounted upon a reciprocating head 134 guided in ways 135. The head i134 is carried by a connecting rod 136 secured thereto by a pivot 137. The inner end of the shaft 92 carries a head 138 having a stub shaft 139 thereon in offset relation to the shaft 92. The cran'k end of the connecting rod 136, has a split bearing 141 which -is suitably tightened upon stub shaft 1139 by a screw 142. The shaft has a brake drum 143 thereon engaged by a brake band 144 on which a predetermined tension is provided by a `spring 145 on an adjustable screw 1-46. The gear 91 has a clutch plate 147 on the side thereof opposite to that having the bevel gear 93 thereon. The gears 91 and 93 and the clutch plate 147 are freely rotatable upon the shaft 92. A spring pressed pin 1'48 is carried within the cylindrical extension of the brake drum e143, having a finger 149 thereon which is engageable by a cam surface 151 on the inner end of the shoe 118. Upon the retraction of the shoe 1:18 thro-ugh the advancement of the cam lug 108, the pin I148 will be urged into the slot 150' in the face of the clutch plate 147 and the continuous driving of the gear 91 will rotate the Shaft 92. During this initial rotation, the shoe 118 will be moved forwardly to have the cam surface 181 in position to be engaged by the extending nger 149 which will produce the retraction of the clutch finger 148 and separate the brake drum extension from the clutch plate and the driving gear 91 which continues to rotate. The pressure on the brake drum 143 by the band 144 will immediately stop the rotation of the drum and the reciprocation of the connecting rod 136. With this arrangement, selected lengths of springs may be `severed from the formed strip 82 as it is advanced step by step bet-Ween the dies 132 and 133. The dwelling of the spring is synchronized with the downward movement of the head 134 so that the cutting and forming operations on the ends will occur when the spring strip is stationary. For a more detailed understanding of the machine and its operation, reference may be had to the expired patent of F. J. Horton, No. 2,188,408.

In FIGURES 7 to l2, the cutoff and forming dies 132 and 13-3 and their operation are clearly illustrated. The

upper die 133 is provided with a forming finger 154, two pairs of downwardly extending ngers 155 adjacent to the outer edge thereof and a shearing blade 156. The bottom die 132 has a shearing slot 157 and cylindrical apertures 158 which receive the pins 155. As illustrated in FIGURES 7 and 8, the elements 154, 155 and 156 are above the surface of the die 132 so that the formed spring strip 83 may be advanced therethrough. When the clutch plate 147 is enga-ged by the pin 148, the movable die 133 is moved downwardly to the position illustrated in FIGURES 9 and 10 wherein the end 74 on the strip is i severed from the bars 75 and the bars are deiiected outwardly to form an offset 159 in each free end of the severed spring strips. The pins 155 back up the bars 75 as the sloping edges of the forming finger 154 deflect the portion 159 outwardly between the pin. The upper die 133 -is immediately retracted during the single rotation of the brake drum 143, and the spring strip 83 is again advanced by steps through the die elements.

As illustrated in FIGURES 17 and 18, a clip 161 is employed for supporting the end bar 75 on a rail 162 of a supporting frame. The clip has a bottom fiange 163 and a top tiange 164 joined by a U-shaped web 165. The web is split at the center so that when the fianges are moved linto parallel relationship, extending portions 166 of the flanges -will be provided in the central area of the clip. The extending portions 166 receive the offset portion 159 and pre'vent the rotation of the end bar and its endwise movement. Aligned apertures are provided through the flanges 163 and 164 through which a nail 167 is driven to lock the offset portion 159 in fixed position. The ange 163 is further secured to the rai/l 1-62 by a pair of nails 168 extending through a pairV of .additional apertures in the flange 163.

The inwardly bent edge portion 74 formed by the boss 73, as illustrated in FIGURE 4, overstresses the wire section which when released produces the straight edge portion 74, as clearly illustrated in the figure. When it is desired to have .an outwardly presented loop portion 17'1 on the spring edge, as illustrated in FIGURE 16, a device is employed as illustrated in FIGURE 14. In this arrangement, the boss 71 on the arm 65 supports a tool 1-'12 which is adjustably secured therein by screws 173 and a backup screw 174. A boss 175 projects from the end of the tool 172, having an angular end portion which further defiects the wire end portion 74 to produce a set therein which will provide the outwardly presenting notch in the end portion, as illustrated in FIGURE 16. It will be noted that the heads 41 have a greater recess 175 therein to permit the greater overstressing of the wire portion 74. Thus the normal operation of the bellcranks 62 and 63 produces the spring strip and the final movement of the arms thereof reforms the end sections of the 4strip into any desired shape such as the straight portion 74 as illustrated in FIGURE 15 or the sinuous portion 17|1 as illustrated in FIGURE 16.

Heretofore costly machines were employed to produce sinous spring strips having straight bendable side bars. The present arrangement permits the modification of a standard spring forming machine to produce the straight side bars or similar forms at the side edges of spring strips so tha-t short runs on the machine are made commercially feasible. The novelty of the invention resides in the further forming of the edge side sections of the wire after the spring like strips have been formed at the time of the forming operation so that no additional cost will be encountered when completing the operation to produce the different types of spring strips.

What is claimed is:

1. In a machine for forming flat sinuous spring strips, a body having a pair of rows each containing a plurality of reciprocable pins, means for forming a wire about said pins to provide parallel straight bars joined by end sections, and means for reforming the end sections to a different shape at the time a next adjacent bar is formed.'

2. In a machine for forming fiat sinuous spring strips, a body having a pair of rows each containing a plurality of reciprocable pins, means for forming a wire about said pins to provide parallel straight bars joined by end sections, and means for reforming the end sections to a different shape at the time a next adjacent bar is formed, said pins having a recess across the face at which the end section is formed and said forming means defiecting the end section into said recess to a degree to straighten the section and haveit disposed substantially normal to the cross bars when released.

3. In a machine for forming fiat sinuous spring strips, a body having a pair of rows each containing a plurality of reciprocaole pins, means for forming a Wire about said pins to provide parallel straight bars joined by end sections, and means for reforming the end sections to a different shape at the time a next adjacent bar is formed, said pins having a recess across the face at which the end section is formed and said forming means deflecting the end section into said recess to a degree to change the shape of the section.

4. In a machine for forming a flat sinuous spring strip, a plurality of pins having heads thereon the outer faces of which are recessed, a pair of swinging arms, and means on said arms for forming the wire about said heads to provide parallel cross bars joined by end sections located across the head recesses, and means on said arms for deflecting the wire of the end sections into the recess to shape the end sections to a different form.

5. In a machine for forming a fiat sinuous spring strip, a plurality of pins having heads thereon the outer faces of which are recessed, a pair of swinging arms, and means on said arms for forming the wire about said heads to provide parallel cross bars joined by arcuate end sections located across the head recesses, and means on said arms for defiecting the wire of the end sections into the recess to so reform the wire thereat that when released the wire section will be straight and disposed substantiaily normal to the cross bars.

6. In a machine for forming a fiat sinuous spring strip, a plurality of pins having heads thereon the outer faces of which are recessed, a pair of swinging arms, and means on said arms for forming the wire about said heads to provide parallel cross bars joined by arcuate end Sections located across the head recesses, and means on said arms for defiecting the wire of the end sections into the recess to so reform the wire of the section to produce an outwardly facing section at the side edges of the spring strip.

7. In a machine for forming wire into a sinuous shaped spring having parallel cross bars joined by end sections,

die means for cutting sections from the strip, and meansV in said die means for defiecting the central portion of the adjacent severed bars away from each other to form an inwardly extending offset therein in the plane of the spring.

8. In a machine for forming wire into a sinuous shaped spring having parallel cross bars joined by end sections, die means for cutting sections from the strip, means in said die moans for defiecting the central portion of the adjacent severed bars away from each other to form an inwardly extending offset therein in the plane of the spring, and a clip having a pair of extending flanges joined by a U-shaped web, the central portion of which is open to receive said offset and severed bar.

9. In a machine for forming wire into a sinuous shaped spring having parallel cross bars joined by end sections, die means for cutting sections from the strip, means in said die means for defiecting the central portion of the adjacent severed bars away from each other to form an inwardly extending offset therein in the plane of the spring, and a clip having a pair of extending flanges joined by a U-shaped v eb, the central portion of which is open to receive said offset and severed bar, said flanges having aligned apertures located adjacent to the central portion 7 8 through which holding means for the clip locks the offset 2,832,392 4/ 1958 Spitz 140-71 portion of the severed bar in said web extensions. 2,995,155 8/ 1961 Fisher.

2,998,045 8/ 1961 Horton. References Clted 3,147,779 9/1964 Brown 14o-105 UNITED STATES PATENTS 10/ 1918 Bloemker 140-71 FOREIGN PATENTS 10/1932 Dailey 11111140-71 662,161 4/1963 Canada 1/ 1940 Horton. 1/1955 W eiss 140 105 CHARLES W. LANHAM, Pnmary Exammer. 1/ 1957 Gier 140-71 10 E. M. COMBS, Asssant Examiner. 

